Does it affect my pets the steam of my electronic cigar?
Although Propylene Glycol is generally recognized as safe for humans and most domestic animals, it is cats that actually have a unique sensitivity to the chemical.
This may cause concern for some vapers, since most e-liquids are mainly composed of Propylene Glycol. Upon learning this, it is natural to wonder if it would be better to switch to liquids based on vegetable glycerin (VG), or just not vape near your cat, but after knowing more about the subject, you can see that exposure to Propylene Glycol in Second-hand vaping is unlikely to cause a problem.
Why is Propylene Glycol bad for cats?
It is well established that Propylene Glycol is not good for cats, and this is due to its effect on red blood cells: it increases the amount of "Heinz bodies" between them. These are basically pieces of hemoglobin that have been "denatured," which means that they have lost their ordinary structure and therefore are not as good at transporting oxygen.
This occurs due to the action of "free radicals" (reactive chemicals, which contain oxygen), and the process is not limited to cats. Generally speaking, the spleen of the animal repairs the damage or gets rid of the blood cells, but if a large number of blood cells are sacrificed due to Heinz's bodies, this exposure can lead to anemia (which can basically defined as a low blood cell count.) Propylene glycol is not directly responsible for this oxidative damage in cats, but it is assumed that the intermediary molecules when they break down in the body are.
In cats, there is also a specific weakness of Heinz bodies because they form more easily than other animals and their spleen is also quite ineffective in removing them. Even in healthy cats, approximately 1 to 2 percent of red blood cells will have Heinz bodies, but their increased risk means that they should be minimized as much as possible.
Propylene Glycol was used as a preservative and a source of carbohydrates in cat food (cheap) until 1992, and although it is still used in food for the rest of the animals (and ours), the FDA officially declared that it is unsafe for cats in 1996. Onions also cause Heinz bodies in cats, which is why they should also be left off the menu.
Should I worry about using an E-Cig around my cat?
The fact that the problem was detected because Propylene Glycol was put in cat food until the 1990s should dispel some fears immediately. Research has shown that the effect is dose dependent: in the test, five weeks of feeding cats with propylene glycol in food as the amounts (1.6 g per kg of body weight) increased the percentage of bodies of Heinz at 28, and after three weeks of eating higher amounts (8 g per kg) they rose to 92 percent.
For an ordinary cat (weighing about 4 kg), the lowest dose used in the study would be 6.4 grams (or about 12 percent of its diet), which is a hell of a lot more compared to the amounts that you can really expect a cat that is inhaled by being in the room with someone who is vaping. If you are going to mix e-liquid and allow your cat to literally drink from its Propylene Glycol, then obviously there would be some cause for concern, but if you are only using an e-Cig there is very little to worry about.
The best advice is simply to exercise some caution about where the steam blows, as in, do not blow directly on your cat's face (even if it is fun), and do not vape on her food or water. The objective of the game is to minimize your cat's exposure, but as long as you avoid these more obvious forms of exposure, vaporized propylene glycol is nothing to worry about.
Conclusion - Keep an eye on the symptoms
Although it is very unlikely to occur, it is still worth looking at the symptoms of Heinz body anemia in cats anyway. These include skin discoloration, fever, loss of appetite, weakness (which develops rapidly), pale lips, mouth and gums, and - in severe cases - rust colored, reddish brown urine. Even if it is not anemia or something related to Propylene Glycol, it is obvious that it is still worth going to the veterinarian if your cat has some of these symptoms, because they are likely to be indicative of a problem. Due to the concentrations involved, there is little risk of anemia with Heinz bodies unless they constantly direct their steam towards their cat - or go on to buy their cat food from the 1980s - but it is worth being cautious of anyway.